The present invention relates to a new and distinct variety of apple tree, specifically a dwarfing rootstock variety of apple tree which is capable of reproduction from hardwood cuttings and which exhibits excellent disease and insect resistance, environmental adaptability and graft compatibility.
In Japan, cultivation of dwarfed apple trees to date occupies 23% of the total cultivation area, but many problems remain to be solved. The dwarfing apple rootstocks mainly used in Japan at the present time are `M.26` (unpatented) and `M.9` (unpatented), but these M-line dwarfing rootstocks are associated with such problems as outbreak of violet root rot, cankers and crown rot, and weak tree vigor due to development of burrknots. Also, because the M-line rootstocks cannot be propagated by hardwood cuttings in the manner of the traditional `Maruba Kaido` (Malus prunifolia BORKH. var. ringo Asami) (unpatented), it is common in Japan to graft M-line stocks onto `Maruba Kaido` for use as double stocks. For this reason, extra costs are incurred for nursery stock production, while high growth after planting prevents adequate performance of the characteristics of the dwarfing rootstocks.
It is an object of the present invention to improve these disadvantages of current dwarfing rootstock varieties, and to raise a rootstock variety which is capable of reproduction from hardwood cuttings and which exhibits excellent disease and insect resistance, environmental adaptability, graft compatibility and dwarfing capability.